Jump to content
Sign in to follow this  

Radiator question.

Recommended Posts

There is no thermostat on 99% of dirtbikes,

 

perhaps some very rare enduro/dual sport engines have one.

Edited by mlatour

Share this post


Link to post
Share on other sites

Some of the KTM lineup is equipped with thermostats.  That's pretty much it. 

 

That lack of a thermostat can cause problems in some EFI bikes that automatically compensate for cold conditions.  It can cause the mixture to run excessively rich, and result in oil contamination from fuel, high fuel consumption, etc.

Share this post


Link to post
Share on other sites

DRZ S/SM models have one.

I would venture most road legal bikes would have one due to the speeds they are capable of running. At 50 mph constant cruse, a typical modern engine would get pretty cooled off. My DRZ SM has a temp gauge. I can watch the radiator hit about 150 then see the thermostat close and the radiator temp drops to about 135 and the cycle repeats. Note I am mentioning radiator temps and not engine temps. I believe the DRZ thermostat opens about 190f or so. During slow rides (under 30) and a hot day, the temp will hold steady at 190+ at the radiator, telling me the thermostat is always open.

I suspect (guess) that the Honda CFR250F/L have thermostats too. I'd also venture a fair assumption that all FI non-race bikes have them and will have them due to it making fuel management easier.

Share this post


Link to post
Share on other sites

I think pretty much all KTM EFI dirtbikes have a thermostat now.  I would bet the KTMusky's do as well.  Not sure on the Beta's, but I wouldn't be surprised.

Share this post


Link to post
Share on other sites

I have Vapors on two of my bikes, air cooled & water cooled, and see the same trends in engine and coolant temperatures as noted by William1.  Also the wide range of operating temps really does affect jetting and engine operation on both of these bikes. 

 

I have another water cooled bike with a single small radiator and fan. The fan is constantly on and off, which keeps the engine temp near the fan stat setting. Its engine operation is more consistent than the other two bikes.  So I've considered adding a thermostat to the water cooled bike.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...